I am trying to load a very simple macro in root, I keep getting the following message:
Warning in TClass::TClass: no dictionary for class TBranchRef is available
Warning in TClass::TClass: no dictionary for class TRefTable is available
I am also unable to load a tree which the rootfile contain.
the code i used is :
TCanvas *effec = new TCanvas(“effec”,“effec”,1);
TTree *treeentries = new TTree(“treeentries”,“treeentries”);
TFile *file_1 = TFile::Open(“milagroTrigger_Jan_31.root”);
what root version do you use, on what platform? What root version was used to write the file? You’ll have to use a root version that contains TBranchRef (>=4.01.02 / 4.02.00), otherwise root can’t know these types when reading your file - that’s what it’s warning you about.
You should still be able to get the tree from the file, though, but not the way you’re trying to do it. See $ROOTSYS/tutorials/tree1.C, method tree1r.
Thank you Axel,
The root version I am using is 4.00.08. is that too old?
I forgot to mention that I am running a fermilinux OS.
As I said: it should be >=4.01.02 / 4.02.00, and 4.00.08 is not. But as I also said: this should not prevent you from reading the file, if you stick to the tutorial.